Massive pericardial effusion, yet no signs of tamponade!

Our patient was incidentally detected to have 32 mm secundum ASD with deficient postero-inferior margin. Pericardial patch closure of the defect on cardiopulmonary bypass through the right posterolateral thoracotomy was uneventful; she was shifted to the ward on the 2nd day after chest tube removal. Although she remained asymptomatic, predischarge echocardiogram on the 6th day showed no residual ASD, good ventricular function, a massive pericardial effusion, and right pleural effusion, with the heart swinging in the pericardial fluid space [Figure 1 and Video 1]. A communication created between the right pleural and pericardial cavities during the postero-lateral thoracotomy served to reduce the pericardial pressures in spite of holding 1.2 L of fluid. When intrathoracic pressures fell during inspiration, color Doppler indicated the movement of pericardial fluid into the pleural cavity [Figure 2 and Video 2]. This inspiratory reduction in pericardial volume permitted unhindered systemic and pulmonary venous return. There was no right atrial or ventricular diastolic collapse, and mitral and tricuspid flows were normal [Figure 3 and Video 3]. After aspirating sanguinochylous fluid with high triglyceride levels using a percutaneous pigtail catheter and dietary modifications, she was discharged home the next day. There was no recurrence at 1-week and 1-month follow-up. The nature of fluid and relief after single aspiration indicates the etiology being small vessel and lymphatic injury during dissection.